Dont know about the compress part. However is you search in C90 for "Posting Description" you will find multiple instances where you could replace that with a Description from the line.
Different dimensions can cause the lines to not compress.
Have a look at the primary key of the invoice posting buffer, and how it is used to join/compress the purch. lines into GL Journal Lines.
Answers
Have a look at the primary key of the invoice posting buffer, and how it is used to join/compress the purch. lines into GL Journal Lines.